Electric clothes driers are heated by air forced over an electric resistance wire. In one type the wire is a coiled wire supported by insulators carried by an open rectangular frame and arranged in longitudinal parallel rows on each side of the frame. In effect this provides two parallel planes of heater coils, one on each side of the frame. Air flows across the frame and is heated by contact with the wires and to some extent by adjacent duct surfaces which, of course, are heated by radiation. In was generally thought this arrangement was satisfactory.